This invention relates to electronic musical instruments using multiplexed keying information, and to automatic playing devices for such instruments.
An object of the invention is to eliminate the "mechanical" nature of the musical effects generated by an automatic playing device by introducing an extra measure of direct human control over the operation of the device in the time domain, thus placing ryhthm and phrasing directly under human control, and making an accompaniment generated by such a device better adaptable to the behavior of soloists, choirs, congregations or other accompanied groups of musicians. The invention can be used for accompaniment of a choir or church congregation in the absence of a competent organist, or could be incorporated into the auto-play features on an electronic organ or synthesizer intended for home or entertainment use.
Advantages which the invention offers over conventional auto-play mechanisms include its relative simplicity and the retention of direct human control over rythm and tempo.
Automatic playing devices with tempo control are known. U.S. Pat. No. 3,890,871, for example, discloses a sequencing apparatus for storing melodic and rythmic information responsive to electric signals produced by playing an electronic instrument keyboard. The sequencer develops digital codes representing the durations between successive notes, and in addition converts the analog signals representing the pitch of a note into digital form. Upon command, the digital pitch information is reconverted to analog form and returned to the electronic instrument at a selectable speed above or below the tempo of the melody originally played on the synthesizer keyboard. Thus, the tempo of melody playback can be made faster or slower than the tempo of the original melody.
U.S. Pat. No. 4,345,501 discloses a tempo control device for automatic performance where the tempo of the automatic accompaniment is speeded up or slowed down to follow that of manual melody performance as the tempo of the manual performance changes during the performance. The invention disclosed in this patent permits automatic accompaniment to follow the tempo of manual melody play.
U.S. Pat. No. 4,476,766 discloses an electronic musical instrument which generates accompaniment and melody sounds with different tone colors. Predetermined performance keys in a group for a low octave section are used as read-out keys for reading out accompaniment memorized in a first memory, and the other keys in the keyboard are used as read-out keys for reading out melody memorized in a second memory. There is no mention in this patent of tempo control in what is recorded and no mention of playback tempo control other than that which results from random key depressions.
There is a need for a device which provides for automatic playback of both melody and accompaniment while also providing retention of direct human control over playback rythm and tempo. This invention meets that need.